X-ray tube



Dec. 26, 1944. Z, J, ATLEE 2,365,855

X-RAY TUBE Filed Dec. 7, 1942A I N VEN TOR.

Patented Dec. 26, `1944 Electric X-Ray Corporation, Chicago, Ill., acorporation of New York Application December 7, 1942, serial No. 468,066

` (ci. 25o-144) 8 Claims.

'I'he present invention relates in general to electronics and has moreparticular reference to an improved high frequency electronic tube, theinvention relating especially to an X-ray generator.

An important object of the invention is to provide an electronic tubeincluding an anode, a

cathode, and a sealed envelope enclosing the same, having enclosedwithin the envelope transformer means for supplying relatively highoper-` ating voltage between the anode and cathode, including facilitiesfor energizing the transformer means from a relatively low voltageenergy source outwardly of the envelope.

Another object ofthe invention is to provide an electronic tubeincluding an anode, a cathode. and a sealed envelope enclosing the same,having enclosed'wthin the envelope oscillator means for supplyingoperating energy at relatively high frequency between the anode andcathode, including facilities for energizing the oscillator means from alow frequency powersource out` wardlyof the envelope.

Another important object is vto provide an electronic tube havingtransformer and associated oscillator means contained within theenvelope of the tube, together with an anode and cooper-` ating cathodewhereby all of the high voltage and high frequency elements required tooperate the electronic device are contained within the sealed envelopeof the tube, only relatively low volt` age normalfrequency equipmentbeing required outwardly of the tube for the operation of the same.

`Still another important Aobject isto provide an electronic Atube havingmeans forming an oscillator'built into` the anodeV structureof the tube;

A further importantv object is to provide an electronic tube havingtransformer means en closed within the tube envelope wherein a windingof. the transformer `means is utilized as a support for the anode of thetube. i

Another object is to provide an electronic tube having a main anode andcathode enclosed in an envelope. together with anoscillatorincluding acathode wherein the main cathode 'and the oscillator cathode comprisefilaments energized from a power source outwardly of the envelopethrough a common conductor extending through a seal formedin a wallofthe envelope. Y

The foregoing and numerous otherl important objects, advantages, andinherent l functions l of the invention will be `fully understood fromthe following'descriptiomwhich, taken in connection with theaccompanying drawing, discloses a pref -ferred embodiment of theinvention.

Referring to the drawing:

Figure 1 is a diagrammaticillustration of an electronic device embodyingthe present inven. tion;

. Figure 2 is a sectional View taken through a preferred form of deviceembodying the invention; and

Figures 3 and 4 are sectional views taken substantially and respectivelyalong the lines 3-3 and 4-4 in Figure 2.

'I o illustrate the invention the drawing shows an electronic devicecomprising an X-ray generator having an anodel I3 forming a targetsurface I5, and a cathode comprising a head and an electron emittingfilament I9, the anode and cathode being enclosed and supported within asealed envelope 2| formed with an X-ray emitting window 23 opposite thetarget surface of the anode. Also enclosed and supported within thesealed envelope 2| is a transformer 25 and an oscillator 3|, thetransformer 25 comprising a primary low voltage Winding 2l and asecondary high voltage winding 29. The oscillator comprises a cathode 33whichfmay be formed as a filament, an anode or plate 35 and a. grid 3ldisposed between the cathode and the plate for the purpose ofcontrolling electron flow therebetween.

The several elements are interconnected within the y envelope, andconductors extending through seals 39 in the envelope walls are provided-for electrically connecting the interconnected elements within theenvelope with a suitablevpower source outwardly of the envelope. To thisendthe plate 35 of the oscillator maybe electrically connected, as byconductor means 4|, with the interconnected ends of the transformerwindings 2l and 29, the low voltage winding 21 being also connected witha conductor 43 which extends outwardly of the envelope through a seal39. The high voltage winding 29 of the transformer is electricallyconnected with the anode I3, as by conductor means 45. The grid 31 ofthe oscillator is connected to a conductor 4l which extends outwardly ofthe envelope through a seal 39, and the filaments |9 and 33 areconnected in common to conductor means 49 and are individuallyconnected, respectively, to separate conductors 5| and 53. Each of theconductors 49, 5| and 53 extend outwardly of the envelope through.suitable seals 39.

Any suitable means may, of course, be employed for supporting theelements .within the envelope 2|, although, as .shown more particularlyin Figure 2, the elements are preferably all supported on a singlemounting 55 which forms a sealed closure at one end of the envelope andthrough which the conductors 41, 49,

mote from the seal 59, being sealingly secured to the support member 55,which preferably comprises a metal plate sealingly brazed to the shortsleeve 6I. The envelope 2I, including the reentrant portion 51, thesleeve 6I and the plate 55 thus form a sealed enclosure,4 and the plate55 forms a support on which the elements of the device are carried. Theplate 55 is formed with a plurality of openings 63 therethrough, inwhich the conductors 41, 49, 5I and 53 are sealingly mounted andpreferably insulated from the metal plate 55 by glass' globulesextending in the openings 63 and forming the conductor seals 39. Withinthe envelope the mounting 55 preferably carries a cylindrical frame 65enclosing a space 61 adjacent the inner face of the plate 55. Within theframe 65 the oscillator grid 31 is arranged preferably in the form of ahelical coil which is supported on and electrically connected at one endto the conductor 43 which extends through and is supported on the plate55. Within the helical coil 31 extends a support frame 69, preferablycomprising legs of electrical conducting material, the lower ends ofwhich are mounted on insulated supports carried by the plate 55, atleast one of which supports extends through the plate to form a part ofthe conducting means 49. The support frame 69 extends outwardly of theframe S5 within the envelope 2l and carries the cathode I1 in which ismounted the filament I9. One end of the lament I9 is preferablyelectrically connected to the head I1, and hence through the frame 99 iselectrically connected with the conductor 49. The other end of thelament I9, is electricallyv connected with the conductor means 53whichis insulated from the head I1, as by means of insulating blocks 1I,and the conductor 53 extends from the filament within the frame 69 andthence outwardly of the envelope through a seal 39. The oscillatorfilament 33 preferably comprisesa helical coil disposed within the space61 in position enthe frame 65 which is of metal and which forms theplate or anode of the oscillator 3|. The plate remote end of thetransformer winding 21 is connected to the conductor 43 which extendsoutwardly of the envelope through a seal 39;

After the elements have thus been assembled within the envelope 2|, thesame may be evacuated and conditioned for service, as by connecting theenvelope with an exhaust pump, the connection being sealed off, as at15, at the conclusion of the tube conditioning period.

Devices embodying the herein described features have the advantage ofincluding in a single envelope all of the frequency and high voltageapparatus required for the operation of the vtube at high voltage andfrequency. The problems of insulation and protection of high voltage andfrequency apparatus outwardly of the tube are thus entirely avoided,since the tube of the present invention may be operated from a lowvoltage source, which, as shown in Figure '1, may comprise a transformer11 powered from anv energy source, such as a commercial distributionsystem, at one hundred ten volts and sixty cycles, the transformer 11being designed to deliver power at, say, one thousand volts forapplication between the conductors 43 and 49, and to deliver power atlesser voltages between the conductors 49, 5I and 53, the conductors 41and 5| being electrically interconnected outwardly of the envelope, asby reactive means 19, for the control of the oscillator within the tube.

It is thought that the invention and its numerous attendant advantageswill be fully understood from the foregoing description, and it isobvious that numerous changes may be made in the form, construction andarrangement of the several parts without departing from the spirit orscope of ther invention, or sacrificing any of its attendant advantages,the form herein disclosed being a preferred embodiment for the purposeof illustrating the invention'. Y

The invention is hereby claimed as follows:

1. An electron ilow device comprising a sealed envelope, an anode andcathode in said envelope, a transformer and oscillator means comprisingan electron source, a plate and a gridwithin said circling the conductorv53, one end of the filament 33 being electrically connected with theconductor 5I which extends outwardly of the envelope through a seal 39in the plate 55.

The transformer 25 comprises the primary winding 21 and the secondarywinding 29, both of which comprise helical coils disposed one within theother and both encircling the cathode filament and its support. Thetransformer coils are each mounted at one end on the frame 65 and extendthence in concentric relationship toward the end of the tube remote fromthe plate 55. The secondary winding 29 extends beyond the winding 21 andsubstantially to the end of the tube, and is fitted with a preferablymetal shell 13 which forms a mounting for the anode I3, which is thussupported on the .transformer winding 21 in position opposite thecathode I9. The shell 13 thus forms the electrical connection 45 betweenthe transformer winding 29 and the anode I3.

It will be noted that both windingsf21 and 29 of the transformer arecommonly connected with 75 envelope, said transformer having a primarywinding connected with said plate and outwardly of Athe envelope, and asecondary winding connected between said plate and said anode andsupporting said anode, said electron source being connected with saidcathode,and means to energize said cathode and said electron source froma power source outwardly of the envelope.

2. An electron flow device comprising a sealed envelope, an anode andcathode in said envelope, transformer and oscillatormeans within theenvelope and operatively connected with the anode and cathode, saidloscillator means .comprising an electron emitting element, said electronemitting element and said, cathode each comprising a lament,said'transforrner comprising co-axial primary and secondary coils, saidsecondary coil being arranged to encircle the filament of said cathode,and means comprising a common conductor extending outwardly of saidenvelope for energizing said filaments for electron emission Y `velopehaving a metal envelope portion forming a mounting, means forming anoscillator plate on said mounting, means on and insulated from saidmounting and forming an oscillator grid adjacent said plate, an electronemitting nia-- `ment on and electrically insulated from .said mounting,an anode forming an X-ray generating target, a cathode on and insulatedfrom said mounting in position to deliver electrons on said target, andmeans forming a transformer comprising windings electrically connectedon said oscillator plate, one of said windings carrying said anode andthe other having a connection extending outwardly of said sealedenvelope.

5. An X-ray generator comprising a sealed envelope having a metalenvelope portion forming a mounting, means forming an oscillator plateon said mounting, means on and insulated from said mounting and formingan oscillator grid adjacent said plate, an electron emitting element onand electrically insulated from said mounting, an anode forming an X-raygenerating target, a cathode insulated from said mounting in position todeliver electrons on said target, and means forming a transformercomprising windings electrically connected on said oscillator plate, oneof said windings carrying said anode and the other having a connectionextending outwardly of said sealed envelope.

6. An electron flow device comprising a sealed envelope, an anode andopposed cathode in said envelope, a transformer and oscillator meanswithin the envelope and electrically connected with the anode andcathode, said oscillator means comprising a plate member, saidtransformer comprising a winding supported on said plate member and inturn carrying said anode in opposing relation with respect to saidcathode.

'7. An electron flow device comprising a sealed envelope, an anode andopposed cathode in said envelope, oscillator means within the envelopeand electrically connected with theanode and cathode, said oscillatormeans comprising a shell member forming an oscillator plate, anoscillator grid and electron emitting means enclosed within said shellmember, said anode being supported on said shell member in opposingrelation with respect to said cathode.

8. An electron flow device comprising a sealed envelope, an anode andopposed cathode in said envelope, transformer means and oscillator meanswithin the envelope and electrically connected with the anode andcathode, said oscillator means comprising a shell member forming anoscillator plate, an oscillator grid and electron emitting meansenclosed within said shell member, said transformer means comprising awinding supported on said shell member, said anode `being supported onsaid winding in opposing relation with respect to said cathode.

zED J. ATLEE.

